This application relates to a system which combines a heat exchanger for de-icing fuel in a gas turbine engine with a drain for draining a compartment in an associated aircraft.
An auxiliary power unit “APU” is often provided along with a main gas turbine engine on an aircraft. The APU typically includes a small gas turbine engine, and is started to provide power, or bleed air for the Environmental Control System typically before the main gas turbine engines are started.
The fuel leading to the APU gas turbine engine passes through a filter on the way to a the APU. During ground and flight cycles, it may sometimes be necessary to start the APU. Often the aircraft operates at very low temperature. At low temperature, fuel icing can block the fuel filter. Thus, it is known to utilize hot oil from a gear box to heat the fuel in a heat exchanger before it reaches the filter.
It is also typically necessary to drain collected fluid from a housing or compartment in an aircraft. There is a negative pressure inside this compartment if the compartment has an eductor system, and this can complicate proper gravity draining of the APU compartment.